Depends on what DVD box sets you're looking for. I've gotten pretty cheap DVDs from Deep Discount. Otherwise what I like to do is go to DVD Price Search, where you can compare prices for a number of places, including Deep Discount.
Often the best place to buy secondhand DVD box sets is a local store where CDs, DVDs and electronics are bought, sold and traded. Failing this, used DVD boxed sets of many types are often available on Amazon and eBay as well as secondhand book and audio dealers like Abebooks or Alibris.
These days, Baby Einstein DVD sets are generally available through mass merchandisers (Amazon) or through auctions or second hand shops. The reason for this is that the DVDs were discontinued due to a controversy surrounding their purported effectiveness and appropriateness.
There are a couple of places one may purchase the CSI New York DVD box sets. These sites include, but are not limited to Amazon and DVD box city. One may also find box sets on eBay.
There are many different places where a person can purchase DVD box sets. Stores such as, Walmart, Target, Sears, and Barns and Nobles all sell DVD box sets.
There are always used copies on Amazon.
One can purchase the Star Trek original series DVD box sets from multiple online sites. These websites include Amazon, eBay, DeepDiscount, and HarvBooks.
I believe you can purchase those on Amazon.
DVD sets of the television show "Are You Afraid of the Dark" can be difficult to locate in stores. Websites such as Amazon, eBay, and iOffer are the best places to purchase these DVDs.
Some DVD boxed sets offered by Disney include the Disney-Pixar Ultimate Movie Collection, the Walt Disney Animated Anthology and the Walt Disney Collectible Classics Box Set. You can purchase these DVD boxed sets online at the Amazon website.
There are many DVD box sets available for purchase, but the most popular ones from the year 2012 are The Wire, Sex and the City, Twin Peaks, and Band of Brothers.
Nightmare Before Christmas is a popular animated film which has been available on DVD for some years. It can be purchased from online retailers such as Amazon, or from DVD shops such as HMV. Alternatively, second hand copies can be purchased from websites such as Ebay.
The mini series V is available on DVD through the retail website Amazon and costs approximately £7 ($10), with old (second hand) and new copies on sale.
There a few known very trusted sites where one could purchase or browse DVD box sets of movies directed by Clint Eastwood. One of these online sites are Amazon.